In a large mixing bowl, add the heavy whipping cream, powdered sugar, and vanilla extract.
Using an electric mixer, whip the cream mixture on high speed until stiff peaks form (about 3-5 minutes).
Take an 8x8 inch baking dish or similar and start layering: dip each Oreo cookie briefly in chocolate syrup, making sure they’re just coated but not soggy.
Lay the dipped Oreos in a single layer at the bottom of the dish.
Spread a layer of whipped cream mixture over the Oreos, smoothing it out to create an even layer.
Repeat the process by adding another layer of dipped Oreos, followed again by a layer of whipped cream. Continue this process until you run out of Oreos or whipped cream, finishing with a layer of whipped cream on top.
Cover the dish with plastic wrap and refrigerate for at least 4 hours, or overnight for best results. This allows the flavors to meld and the cookies to soften.
Before serving, garnish the top with crushed Oreos and optional mint leaves for a fresh touch.